CBSE Class 10 Science 2020 · Paper 31/5/1 · Question 25(a)

Metals and Non-metals 5 marks Medium

Two ores X and Y were taken. On heating these ores it was observed that

(a)ore X gives $CO_{2}$ gas, and
(b)ore Y gives $SO_{2}$ gas. Write steps to convert these ores into metals, giving chemical equations of the reactions that take place.

Answer

X is a carbonate ore and Y a sulphide ore; calcination or roasting gives the oxide, which carbon reduces to the metal.

The gases show that X is a carbonate ore (for example

ZnCO_{3}

) and Y is a sulphide ore (for example

ZnS

). Ore X, calcination: heat strongly in a limited supply of air,

ZnCO_{3} (s) heat ZnO (s) + CO_{2} (g)

. Ore Y, roasting: heat strongly in excess air,

2 ZnS (s) + 3 O_{2} (g) heat 2 ZnO (s) + 2 SO_{2} (g)

. Reduction: heat the metal oxide with a reducing agent such as carbon,

ZnO (s) + C (s) ⟶ Zn (s) + CO (g)

. The carbonate and sulphide ores of another suitable metal, with correct equations, earn the same credit.

🔒 Step-by-step solution